When describing something as "flabbier", it implies that it has become less firm or toned. However, there are several synonyms that can effectively convey a similar meaning. One alternative word is "softer", which suggests a decrease in muscular or overall body tone. Another option is "looser", indicating a lack of tightness or firmness. Similarly, one could use the term "saggier" to describe something that has lost its previous level of firmness or elasticity. Additionally, the word "fatter" can be utilized to indicate a gain in weight or an increase in body fat. All these synonyms effectively convey the idea of something becoming less firm or toned, allowing for a diverse range of descriptive options.